The main objective of the present work is to carrying out the contingency of renal artery aneurysm. To this purpose blood flow in human artery was simulated by CFD. The model based on ANSYS software package and the inlet velocity profile was assumed to be variable and heartbeat is consider. Two types of renal aneurysm was modeled and probabilities was discussed. Simulation shows type II is more common and have good agreement by clinical reports.